Anyway, to circumvent the issue, I'm cloning it. The initial skybox will have the size of the entire level, then I apply the following code:
skyboxObject.rotateX((float)Math.PI*.5f);//CAN'T rotateMesh() OR clearRotation(): IT'S COMPILED
skyboxObject = skyboxObject.cloneObject();//CLONE IT SO skyboxObject IS A SNAPSHOT OF THE Skybox AS IT WAS CREATED AND DOESN'T MOVE ALONG WITH THE CAMERA
skyboxObject.setCulling(false);
skyboxObject.setCollisionMode(Object3D.COLLISION_CHECK_OTHERS | Object3D.COLLISION_CHECK_SELF );
skyboxObject.setCollisionOptimization(true);
skyboxObject.addCollisionListener(this);//Skybox.addCollisionListener()
And I am setting the skybox visibility to true before checking for collision. No collision is happening.